The present invention relates to vacuum machines and more particularly pertains to a vacuum machine for zipper bag.
There are different types of zipper bags in the marketplace for general household food storage. The structure of these zipper bags can be divided into two types, namely the zipping strip type and the sliding tab type. The zipping strip type is disposed with zipping strips for sealing on the two inner surfaces of the zipper bag opening. The zipping strips are interlockable grooves and ridges corresponding to each other. Users may seal the zipper bag by lightly pressing the zipping strips to insert the ridges into the grooves. However, it is often difficult to press the zipping strips accurately with fingers, especially for zipper bags with relatively wide openings. Users usually cannot seal the whole bag openings and this causes leakage of substance inside and fails to attain the effect of sealing.
The sliding tab type zipper bag is also disposed with interlocking zipping strips on the upper inner surfaces of the bag opening, with a sliding tab provided in addition thereto. The sliding tab is usually like a clamp which clamps the zipping strips in its clamping gap. Users only need to slide the sliding tab along the bag opening and the sliding tab would press and seal the zipping strips, thereby achieving sealing. Although sliding tab type zipper bags can seal bag openings easily, most sliding tabs are primitive in their structure and become loose easily. They are therefore not suitable for prolonged repeated use.
Moreover, both zipping strip type and sliding tab type zipper bags fail to attain the effect of complete vacuum. This is particularly apparent when they are used for food storage. If there is plenty of air inside a zipper bag, food becomes oxidized and rotten easily and cannot be stored for a long period of time. Although there are vacuum machines for vacuum sealing of plastic packaging bags in the marketplace, these vacuum machines are usually of complex structure and are bulky in size, which are not suitable for general household use. Some zipper bags are disposed with unidirectional suction valves for the vacuuming function, but this increases production costs and lacks flexibility. If users need to use zipper bags of different sizes, they would need to buy extra vacuum zipper bags.
Chinese Utility Model Patent No. 02271835.4 discloses a micro vacuum machine which is small and light. It draws out air from a zipper bag through a cylindrical suction mouth inserted into the bag so as to attain the vacuuming effect. However, users still need to press the zipping strips of the zipper bag with their hands when using this vacuum machine, which fails to solve the problem of difficultly sealing the zipping strips accurately. Even if a sliding tab zipper bag is used, users have to remove the suction mouth and zip the sliding tab at exactly the same time. The time lag between the two actions may cause entrance of air into the zipper bag, thereby reducing the vacuuming effect.